Sporulation of B. subtilis could be induced by the stringent response to partial amino acid deprivation; relaxed (rel) mutants could not be induced. The induction was prevented by certain antibiotics when they were added at concentrations at which they had almost no effect on growth. Mutants (spd) were isolated which sporulated continually in a medium (with excess glucose) in which normal B. subtilis strains do not sporulate. Some of them were partially deficient in amino acid synthesis, and the introduction of a (rel) mutation prevented this effect. Other spd mutants sporulated continually when in a rel background; they had 50 percent less than the normal S-adenosyl-methionine (SAM) synthetase activity. Addition of partially inhibitory concentrations of ethionine or seleno-methionine to a rel mutant induced sporulation, and ethionine resistant mutants deficient in SAM synthetase sporulated during growth at increased frequency. Apparently, reduced methylation of some cell component increases the frequency of spontaneous sporulation.